Artificial knee



July 16, 1940. J. J. McCANN ARTIFICIAL- KNEE- Filed June 25, 1937 2Sheets-Sheet 1 INVENTOR.

July 16, 1940. J. J. MCCANN 2,208,275

ARTIFICIAL KNEE Filed June 25, 1937 2 Sheets-Sheet 2 I N VENT OR.

Patented July 16, 1940 UNITED STATES ARTIFICIAL KNEE John J. McCann,Burlin gton, N. J.; J. Conner French, Mercer County, and John A. McCann,

Burlington County, N. J., executors of John J.

McCann, deceased Application June 25, 1937, Serial No. 150,293

2 Claims.

This invention relates to artificial limbs and is concerned primarilywith the knee joints of such artificial limbs.

At the present time there is available to the public an artificial limbincluding a knee joint, which is characterized as including a pair oflinks which are pivotally connected to the thigh piece and shin memberof the leg respectively, and with which links are associated anotherpair of pivotally mounted links that are longer than the first mentionedlinks, and are also connected to the thigh and shin membersrespectively. In order that a knee joint of the type above identiiied beproperly operable, it is necessary that the shorter of the pivotal linksbe movable between the longer pivotal'links. In the now known joints ofthis type this movement is accommodated by making the longer links of anarched or olfset formation whereby space through which the smallerpivotal links may move is provided. However, the use of the now knowntypes of knee joints of the character above-noted is attended by certaindisadvantages which are intended to be improved by the presentinvention.

With the foregoing in mind, this invention has in view as an importantobjective the provision of a knee joint for artificial limbs whichcomprises a pair of joint members, one for the thigh piece and one forthe shin piece of the artificial limb. Each of these joint members isformed with a slot intermediate the faces thereof and which slottedportions are provided with pivotal pins whereby a'link is adapted to bemounted in the slotted portions of the joint members. The longer pivotallinks are pivotally mounted on the outer faces of the joint members, andthus movement of the shorter pivotal link member be tween the longerouter pivotal members is provided. v

Important detailed features of the invention are associated with theprovision of proper pivotal mountings for the above noted link members.

Another important phase of the present invention is the provision of anovel type of structure for positively and rigidly securing the jointmembers to the thigh and shin members respectively. In accordance withthe present invention, the lower end of the thigh member and the upperend of the shin member are each provided with base plates, which aresecurely anchored to the respective members. The joint members of thisinvention are formed with flanges that are adapted to engage the baseplates and be bolted thereto to securely affix the joint members to therespective base plates.

Other important details of the invention are associated in theparticular manner in which the base plates are anchored to the thigh andshin pieces respectively.

Various other more detailed objects and ad- 5 vantages will in partbecome apparent and in part be hereinafter constituted as thedescription of the invention proceeds.

The invention, therefore, comprises an artificial limb including a thighpiece and a shin 1 piece each of which is provided with a base plate atthe extremity adjacent the knee joint of the limb. Each of these baseplates is anchored th the respective'thigh or shin piece by a rigidconnection and securely affixed to each base plate is a joint member,the connection being established by a bolted flange arrangement. Each ofthe joint members is slotted intermediate its faces and a short link ispivotally mounted in said slotted portions. outer faces of said jointmembers are a pair of longer links and in such relationship to theshorter length as to have the latter pass therebetween under certainconditions of movement of the joint members. Each of the joint membersis formed with a shoulder that extends substantially in the direction ofthe link members, and interposed between the shoulders of the two jointmembers is a resilient pad which is designed to be compressed incidentto certain movement of the joint members. This same resilient pad alsocauses movement between the joint members in a manner that will bepointed out in detail hereinafter.

For a full and more complete understanding r of the invention referencesmay be had to the following description and accompanying drawingswherein:

Figure 1 is a side view of that portion of an artificial limb whichembodies a knee joint in accordance with the precepts of this invention,

Figure 2 is a transverse section of the knee joint, bringing out thearrangement of the joint members with respect to the thigh and shinpieces respectively,

Figure 3 is a side view, partly in section and partly in elevation, ofthe joint members per se,

Figure 4 is a view somewhat similar to Figure 3, showing the jointmembers in diiferent relative positions,

Figure 5 is a section through one of the joint members, bringing out themanner in which the outer links are pivotally carried thereby,

Figure 6 is an elevational showing of the parts constituting the pivotalmounting for the outer 5.5.

Pivotally mounted on the 20 receiving the base plate 25.

links. This view shows these parts in an exploded relationship,

Figure '1 is a sectional view similar to Figure 5, developing thepivotal mounting for the inner shorter link,

Figure 8 is an exploded elevational showing similar to Figure 9 of theparts constituting the mounting for the inner pivotal link,

Figure 9 is a viw of one of the joint members with parts broken away andshown in section to develop the slotted construction that accommodatesthe inner link, and

Figure 10 is a side view partly in section, and

partly in elevation of the inner link member;

per se.

Referring now to the drawings wherein like reference characters denotecorresponding parts.

The thigh piece of an artificial limb is represented in Figures 1 and 2by the reference character Ill. The thigh piece If] is of a hollowconstruction that is defined by a front wall ll, rear wall l2 and sidewalls 13, the walls II and i3 being connected by rounded corners tosimulate the appearance of a natural thigh. The front 4 wall H is cutaway as represented by the line at l4 and. the cut away portion isreplaced by a removable piece [5 that may be taken out to obtain accessto the joint mechanism that is obtained between continuations of theside walls i3 and the rear wall I2. A base plate identified at I5 isformed on each side edge with an ear I1, and each of the ears I1 isanchored to the walls ll, l2, and I3 respectively by a nut and boltarrangement referred to generally at l8. Secured to the base plate [6 isone joint member which is referred to in its entirety by the referencecharacter A, of which the detailed construction will be pointed outhereinafter.

The shin piece of an artificial leg is shown at I 9, and the upperportion of this shin piece is hollowed out to accommodate the base plate20. The base plate 20 is formed with a plurality of ears 2] on its sideedges which are bolted to the walls of the shin member l9 that definethe recess Inasmuch as the wall surrounding this recess is thin,permanence and rigidity of the anchorage of the base plate is affordedby having the anchoring bolts shown at 22 pass through the outermetallic shield 23 that is also carried by the shin piece 19. Theconnecting member referred to in its entirety by the reference characterB is carried by this base plate 20 and within the shield 23.

Referring now more particularly to Figure l, the connecting member A isshown as comprising a main body member 24 that is formed with a flange25 that engages the base plate I6 of the thigh piece It and is securelyanchored thereto by the nut and bolt arrangement identified at 26.Extending towards the rear wall l2 from the main body portion 24 of thejoint member A is a nose portion 21 that is slotted as shown at 28 inFigure 3, and extending downward from the main body 24 is a shoulder 29that is also clearly brought out in Figure 3.

The joint member B also comprises a main body portion 30 that'is formedwith flanges 3| that engage the base plate 20 and are connected theretoby bolted nuts identified at 32. Extending rearwardly and upwardly fromthe main body 30 is a nose portion 33 that is also slotted as shown at34. This nose portion 33 defines a shoulder 35.

At this point it is well to note that a pad of a resilient material suchas sponge rubber is interposed between the shoulders 35 and 29 and ispreferably secured to the shoulder 29 in any preferred manner as by anadhesive.

This resilient pad is identified at 36. A short link member 31 has oneend pivotally mounted in the slotted portion of the nose 21 of the jointmember A, the pivotal member being referred to generally by thereference character 38. The other end of the link 31 is pivotallymounted in the nose portion 33 of the joint member B, and the structureof the pivotal connection is identical with that at 38.

The detailed construction of the pivotal con-. nection at 3B is bestdescribed by referring to Figures '7, 8, 9, and 10. This connection isdescribed in conjunction with the joint member A and it is to beunderstood. it is to be repeated in the joint member B.

The nose portion 21 of the jointmember A on each side of the slot 28 isformed with openings 33 that are enlarged as shown at 43. Each of theopenings 39 is lined with a bushing 4| which is preferably of bronze toconstitute a good bearing element. The end of the link 31 which isreceived in the slot 28 is formed with a circular opening 42 andextending through this opening 42 and the bushings 41 is a cylindricalsleeve shaped member 43, the inner surface of which is threaded asindicated at 44 in Figure '1. It is notable that the sleeve 43 isprovided with a slight recess 45 and a set screw 46 has a pointedextremity which is adapted to be received in the recess 45. This setscrew 43 is threaded in that portion of the link member 31 surroundingthe opening 42 and serves to establish a non-rotating relationshipbetween the link member 31 and the sleeve 43.

The screw 41 is threaded into one end of the sleeve 43 and has anenlarged fiat head 48 that is received in the enlargement 4!] of theopening 39 and this screw 41 is duplicated at the other end of thesleeve 43 as shown at 49. The heads 48' of the screw members 41 and 49may be provided with lubricating openings shown at 50.

A pair of link members 5! are disposed on each face of the joint membersA and B and anchored thereto by pivotal connections referred togenerally at 52 and 53. These pivotal connections 52 and 53 are ofidentical construction and only one of them needs here be described forthis specification.

Referring now more particularly to Figures 5 and 6, the main bodyportion 24 of the joint member A is shownas formed with an openingextending transversely there across and identified at 54'. This opening54 is lined by a bearing member 55 which may be of bronze or othersuitable material. The link 5| at the right hand side of 55 is formedwith a threaded opening shown at 5B. A bearing pin of cylindricalformation is identified at 51 and is shown as having an enlargedshoulder which is provided with threads which are complemental to thethreaded opening 56. This threaded shoulder is identified as 58.

The bearing pin 51 terminates in a slotted head 59 that engages againstthe link 5! on its outer face. The link 5i on the opposite face of thebody portion 24 of the joint member A is provided with an opening 50, inwhich fits the free extremity of the bearing pin 51. 'The bearing pin 51is of a hollow formation and the bore thereof is threaded and receivesthe headed screw member 6|, the head 62 of which overlaps the link 5| toretain the latter in position on the bearing pin 51. This bearing 51 isalso threaded at the other end and receives a screw plug 63, the head ofwhich is slotted as shown at 64 to provide for the engagement of a screwdriver therewith. The cylindrical wall of the bearing pin 51 is providedwith a lubricating opening 65 and a suitable lubricant such as grease iscontained in the bore of the bearing pin between the members 6! and 63.It is evident that by screwing plug 63 inwardly, the lubricant'will beextruded through the sleeve 55 to thoroughly lubricate the outer surfaceof the bearing pin with respect to the sleeve 55.

With the thigh piece It) and the shin piece iii of the artificial limbin substantial alignment the pivotal links assume substantially the same:osition which is brought out in Figure 2. If the weight of the weareris applied to the limb, the resilient pad 36 will be compressed in themanner brought out in Figure 3. When the weight of the wearer is removedfrom the thigh piece it the resilient pad 36 will cause a flexing on theshin piece it with respect to the thigh piece it which action iscomparable to natural walking movement. If the shin piece !9 is furthermoved to reduce the angle between this piece and the thigh piece iii,the pivotal mounting of the link 31 will be moved between the links 5iin the manner clearly brought out in Figure 4. It is evident with thearrangement illustrated in the drawings and described in the foregoingspecification it is not necessary to provide any offset or bowedconstruction in the links 5| as the link 37 and pivotal mounting thereofis readily movable therebetween.

While a preferred specific embodiment of the invention is hereinbeforeset forth, it is to be clearly understood that I am not to be limited tobe connected to the shin piece of an artificial limb, said second jointmember having an upwardly extending nose portion defining a shoulderspaced from the shoulder on the first mentioned joint member, said lastmentioned nose being slotted, a link having each extremity disposed inthe slots in the said joint members and pivotally mounted therein, apair of links longer than the first mentioned link disposed on oppositefaces of the joint members and pivotally connected there to theirextremities, and a resilient pad of appreciable thickness which iscarried by one of theshoulders, said pad being movable with the shoulderrelative to the other shoulder and subject to compression by and betweenthe shoulders as said shoulders approach a limit of movement toward oneanother, said compressed pad having a shape of materially reducedthickness whereby energy is stored in said pad, to separate saidshoulders when pressure on the joint is released.

2. A knee joint for artificial limbs comprising a joint member adaptedto be connected to the thigh piece of an artificial limb and beingformed with a nose portion at one side thereof, said joint member alsobeing formed with a shoulder, a second joint member adapted to beconnected to the shin piece of an artificial limb, said second jointmember having an upwardly extending nose portion defining a shoulderspaced from the shoulder on the first mentioned joint member, linkagepivotally connected to each of said nose portions, a pair of linkslonger than the first mentioned linkage and disposed on opposite facesof the joint members and pivotally connected thereto at theirextremities, and a resilient pad of appreciable thickness which iscarried by one of the shoulders, said pad being movable with theshoulder relative to the other shoulder and subject to compression byand between the shoulders as said shoulders approach a limit of movementtoward one another, said compressed pad having a shape of materiallyreduced thickness whereby energy is stored in said pad to separate saidshoulders when pressure on said joint is released.

JOHN J. McCANN.

